Many clinically successful anticancer drugs acting as antimitotics interfere with dynamic instability of microtubules; spindle poisons arrest-dividing cells in G2/M phase of the cell cycle, causing apoptotic cell death. Among the natural products affecting microtubule dynamic are colchicines, the vinca alkaloids, combretastatin A4, epothilane, and taxanes. Chalcones are the flavone precursors that possess the antimitotic activity and possess greater antiproliferative activity. Michael L. Edwards, David M. Stemerick, Prasad S. Sunkara, J. Med. Chem., 1990, 33 (7), 1948-1954. Ahcène Boumendjel,*, Julien Boccard, Pierre-Alain Carrupt, Edwige Nicolle, Madeleine Blanc, J. Med. Chem. 2008, 51, 2307-2310. The anticancer activity of 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones have been reported in 1997. Similarly the new guanylhydrazones from imidazo[2,1-b]thiazoles have shown promising anticancer activity. Aldo Andreani,*, Silvia Burnelli, Massimiliano Granaiola, Alberto Leoni, Alessandra Locatelli J. Med. Chem. 2008, 51, 809-816, Aldo Andreani,*, Silvia Burnelli, Massimiliano Granaiola, Alberto Leoni, Alessandra Locatelli, J. Med. Chem. 2007, 50, 3167-3172, Aldo Andreani,*, Massimiliano Granaiola, Alberto Leoni, Alessandra Locatelli, Rita Morigi, J. Med. Chem. 2005, 48, 3085-3089. Moreover the activity of chalcones was found to be dependent on both A and B rings. Hence some new hybrids were prepared by replacing the B ring in chalcone with imidazothiazole moiety, which is already well known for their antitumor activity. These hybrids have shown potent cytotoxicity in the NCI cell line screen for evaluation of their anticancer activity.
